The casual association of cervical spinal cord ischemia and axonal degeneration in second motor neuron following subarachnoid hemorrhage: Experimental study.

Muscle abnormalities after spinal cord ischemia caused by subarachnoid hemorrhage (SAH) have not been explored for degenerative variations in the soma of second motor neurons of the spinal cord gray matter. This study aimed to investigate histopathological alterations in the gray matter and the role of peripheral nerves in SAH.Twenty-two rabbits were allocated in the control (Group I, n = 5), SHAM (Group II, n = 5), and research (Group III, n = 12) groups. Muscle weakness of the upper extremities innervated by radial nerves was evaluated at the initial day, and outcomes were recorded as control data. Re-measurements were done after injecting 0.5 ml of SF for SHAM and autolog artery blood inside craniocervical subarachnoid space for the study group. After 3 weeks, radial nerve roots, their ganglia, and segments of the spinal cord around C5-6 root entry zones were extracted bilaterally. Degenerated second motor neuron somas and the degenerated radial nerve motor axons at the intervertebral foramen were assessed.

The average degenerated soma intensity/mm³ at the C5-6 levels in the spinal cord was 2 ± 1/mm³, 13 ± 4/mm³, and 56 ± 10/mm³ for Groups I, II, and Group III. The average degenerated axon intensity of radial nerves was 3 ± 1/mm², 34 ± 9/mm², and 234 ± 78/mm² for Groups I, II, and III.

Gray matter ischemia in the spinal cord may lead to axonal deterioration on equal levels at the peripheral nerves with advanced SAH. Detected or undetected spinal SAH should be considered an important factor on the etiology of second motor neuron diseases.